工业相机自热引起像点漂移模型与补偿方法

In order to reduce the influence of temperature on the image point coordinates of industrial cameras in visual measurement, the image point drift caused by the self-heating of the camera was studied, and a compensation method for the thermal image point drift of industrial cameras was proposed. The finite element simulation analysis of the industrial camera model through Ansys Workbench shows that the self-heating of the industrial camera will cause the imaging optical path change and sensor expansion change, quantitatively the influence of the optical path change and sensor expansion on the image point coordinates was analyzed, and the image point drift compensation model was established. A large number of experiments have shown that the image point drift error compensated by the model is reduced from 0.4-0.6 pixel to 0.1-0.2 pixel, which is equivalent to the image point drift suppression effect achieved by hardware thermal control. However, compared with the thermal control device, the method of using the model for compensation has obvious advantages of simple structure and low cost. The temperature compensation model proposed in this research provides a theoretical basis for reducing the image point drift error caused by the self-heating of the camera in the visual measurement.     

应用红外热像技术监测催化装置反再系统

利用红外热像技术对兰州石化公司140万吨/年催化装置反再系统进行监测,通过检测数据判断热设备衬里损伤情况,经判断该套装置部分位置出现缺陷损伤,如果工艺控制稍有疏忽,会导致严重事故。通过本次特护检测,为装置的安全运行提供科学的参考依据。通过无损检测技术的应用,对重点部位实施重点监测,保障装置的正常运行,满足装置生产运行的需求。     

中心遮拦非球面主镜Seidel像差拟合分析的优化

中心遮拦干涉图的圆Zernike多项式拟合存在交叉耦合现象,进而影响到Seidel像差的计算。利用干涉仪数据处理软件提供的Mask功能构造出一系列不同遮拦比的中心遮拦干涉图并计算出其圆Zernike拟合系数,结合自编软件判断出被测非球面镜的中心遮拦比对于5项Seidel像差是否达到阈值,给出了具体的实现流程,并对口径为700mm、中心遮拦比为0．23的抛物面主镜进行了实验研究。分析结果表明,该优化分析方法简单易行,基于标准干涉数据处理软件,无需编写复杂的数据格式转化和多项式拟合程序,即可得到相对较准确的Seidel像差估计值。     

高精度事件计时器的设计与实现

高频率、大范围和高精度是现代卫星/月球激光测距(SLR/LLR)的发展趋势,需要高精度事件计时器作为其时问测量单元.分析研究了事件计时器测量时间的原理,并基于时间数字转换(TDC)和现场可编程门阵列(FPGA)技术,用TDC芯片测量微小时间间隔,同时结合FPGA芯片设计和实现整个高精度事件计时器.进行了信号周期测量实验,结果表明,该测量仪准确度高,标准偏差值优于50 ps,系统误差小于11 ps,量程为24 h,温度漂移小于100 fs/℃,短期稳定性好于±3ps/h.     

测试测量技术：为国防电子工业保驾护航——“首届国际测试与仪器应用论坛”观感

科学是从测量开始的——这是19世纪著名科学家门捷列夫的名言。到了21世纪的今天，作为信息产业的三大关键技术之一，测试测量行业已经成为电子信息产业的基础和发展保障。2006年4月27日，由《电子产品世界》主办的“首届国际测试与仪器应用论坛”吸引了近300名专业听众到会。由于论坛依托于同期举行的国防电子展，因此演讲嘉宾的发言均集中在航天、军工等测试领域。     

电力系统配电网反窃电技术的研究与应用

近年来,国家电网公司通过更新电网设备、提高用电科技化水平等措施,配电网线损率有所下降,但是在一些区域,配电网线损率仍然居高不下,造成了国家电力资源的巨大损失。高科技窃电问题日趋严重,进一步加剧了电网线损居高不下。加之随着新能源发电技术的发展,用户端的多能源发电将直接并入配电网中,对反窃电技术的要求也将越来越高。传统的监测窃电的手段存在查窃电即时性差、窃电后取证困难的问题,并且对分流、强磁铁、遥控器等高科技窃电手段难以有效防护。本文从电力系统的现状出发,通过电能计量原理及窃电原理分析,找出窃电的具体原因,并提出一种有效的反窃电降损方案。     

基于系统建模的四像限光电探测器对准与微位移测量系统

通过对基于四像限光电探测器的对准系统的光路分析,将系统的输入输出关系的确定转化为平面光照面积的计算,并给出了探测器各像限光照面积的求取方法,从而构建了该系统的数学模型.对该系统进行了仿真,并给出了系统的实测结果.仿真结果表明,通过设置不同的米字型标记参数,系统的输入输出关系具有不同的线性度.证明的确存在一个最佳结构参数组合,存在优化的可能.实测结果表明,该系统的最大对准偏差小于2 ,实测偏差小于2.佐证了模型的正确性,表明四像限光电探测器的对准应用可扩展到微量位移的测量.模型省去了繁杂的标定工作,消除了标定引入的非线性误差,提高了探测器的应用效率和准确度,因此具有较高的实际意义.     

阵列透镜测量仪的设计与应用分析

为了解决500mm以上大口径光束波前的实时测量问题,设计了一种波前测量系统,即透镜阵列测量仪,其最大优点是避免了现有的H-S波前传感器所面临的大口径缩束器的加工难题。介绍了该测量系统的组成结构及其测量原理,分析了测量系统在设计中的参数选择,并根据具体的系统参数讨论了测量系统的检测性能。在此基础上,利用数值模拟对1200mm口径光束进行了波前测量的仿真实验研究,分析了测量过程中系统标定对透镜阵列测量仪的作用。仿真实验表明,透镜阵列测量仪能够实现大口径光束的波前探测。     

Tracking of signal subspace projectors

A new subspace tracking approach that directly operates on the projection matrix onto the signal subspace instead of tracking its unitary eigenbasis is proposed. Therefore, the difficulties arising from introducing a calculus on the manifold of projection matrices are overcome by a proper parameterization of the projectors. Simulation results are presented from the field of angular frequency retrieval in array signal processing     

Observations on oblique projectors and pseudoinverses

Oblique projectors (which were examined by Behrens and Scharf (see ibid., vol.42, no.6, p.1413-24, 1994)) are related to earlier work on oblique pseudoinverses and constrained least-squares methods and are reconsidered from the standpoint of orthogonal basis vectors and QR factorizations. Construction algorithms are presented that are numerically more stable than the normal-equations constructions previously used     

Real-time implementation and evaluation of dynamic controlalgorithms for industrial manipulators

The authors explore the real-time implementation of various dynamic control algorithms, which use different levels of information of the dynamics of a robot system, to show the feasibility and effectiveness of such algorithms. For this purpose, the dynamic equations of a robot manipulator based on Lagrange mechanisms are derived, converted to the equivalent dynamics with respect to the actuator, and added to the actuator dynamics. Hysteresis current controllers are used as the torque-type controller. Experimental results indicate that the computed torque and iterative learning control methods perform better than classical proportional-integral-derivative (PID) control and that these algorithms can be effectively applied to controlling industrial manipulators     

LED数字投影机短焦投影物镜设计

为实现LED 数字投影机短距离内投影出更大的画面,文中针对此类投影机的结构特点,通过理论计算和ZEMAX 光学设计软件的优化,开发设计一款适用于LED 光源0.7 in（1 in=2.54 cm）单芯片数字投影机的短焦投影物镜。给出工作波长为462~625 nm、全视场角为84、相对孔径为1:2.4、焦距为10 mm、后工作距离大于20 mm 的镜头设计实例。镜头有较好的成像质量, 在分辨率极限40 lp/mm 处, 0.7 视场以内的MTF 值均大于0. 5,全视场畸变量的绝对值小于1.5%,像质优良。设计结果显示,文中提出的设计方法有利于降低投影系统成本,实现产业化生产。     

低温背景红外场景产生器研究进展

红外场景产生器是红外成像制导半实物仿真中不可缺少的硬件设备之一。随着红外成像探测系统在卫星、深空探测器、空间反卫星武器中的广泛应用,低温背景的红外场景模拟越来越受到重视,发展非常迅速。热电阻阵列红外场景产生器被运用到低温背景模拟中,为产生低温背景,场景产生器需工作在比背景温度更低的温度条件下,因此,通常将场景产生器放在低温真空室中。与该种原理不同,半导体屏式可见光到红外光转换的场景产生器在常温下可以实现低温背景红外场景的模拟。对两种低温背景模拟方法进行了对比,并阐述了低温背景红外场景产生器的研究进展及应用情况。     

Reliability evaluation of adhesive bonded SMT components in industrial applications

This paper compares the efficiency of two thermosetting and one thermoplastic conductive adhesives for surface mount technology (SMT) assemblies. Their reliability is evaluated during accelerated life tests through electrical and mechanical measurements. Contact metallizations are taken into account. Finite element simulations confirm the experimental results, and a parametric study permits us to define some choice criteria for the physical properties of adhesives.     

Performance evaluation of IEEE 802.15.4 sensor networks in industrial applications

Wireless sensor networks have been widely applied in industrial applications especially since the release of IEEE 802.15.4 standard. By participating in an automobile project in which an IEEE 802.15.4 based sensor and actuator network is deployed to measure and control the vibrations of an automotive system, we need to study many metrics of IEEE 802.15.4 sensor networks (e.g., packet delivery rate, latency, and energy consumption) under various sampling rates. In order to provide detailed modeling of hardware and software as well as network behaviors on each sensor node, we conduct plenty of experiments on a SystemC‐based wireless sensor networks simulator IDEA1, which supports the hardware and software co‐simulation of sensor nodes with certain flexibility of abstraction level. Compared with the existing works on performance evaluation of IEEE 802.15.4 protocols, the main contributions of this paper are the comprehensive studies of both beacon‐enabled and nonbeacon‐enabled modes under various parameter settings and the beacon tracking synchronization mechanism in the IEEE 802.15.4 standard, which is ignored in most previous works. Additionally, the in‐depth analysis of simulation results enables us to find the best parameter configurations to different traffic loads and application requirements, which can be used as general experiences for other applications.Copyright © 2014 John Wiley & Sons, Ltd.     

Enhancing reliability in an industrial LAN: design andperformability evaluation

A fault-tolerant fiber-optic LAN (local area network) is presented and assessed. The reliability of this LAN has been increased by introducing redundancy into the physical transmission medium and by providing the network with a monitor process that is capable of detecting and isolating faults automatically. The network is modeled by applying Markov process theory, through which the mean time to failure (MTTF) and performability are assessed. The results obtained show that the network exhibits a significant increase in MTTF and performability, which is all the more evident if the coverage factor c is closer to 1 and if the number of stations is higher. Redundancy in the transmission medium and the monitor process enable the network to overcome the typical reliability limitations affecting ring topologies and allow it to be used in some critical industrial applications     

用于长波红外目标模拟器的DMD衍射特性分析

基于DMD的目标模拟器应用于长波红外波段（8~12 m）时,DMD的衍射效应对系统的成像对比度造成较大影响。为使系统获得高对比度的红外图像,需要对DMD的衍射特性进行分析。首先根据DMD的结构和工作原理,将DMD等效为一特殊的二维闪耀光栅,并利用光栅衍射理论和傅里叶变换,推导出DMD二维光栅衍射模型;然后利用MATLAB对DMD在8~12 m波段的衍射模型进行仿真计算;最后对仿真结果进行了实验验证。通过仿真计算和实验分析得出结论:基于DMD的目标模拟器应用于长波红外波段时,照明光束需要选取合适的入射角;当入射空间方位角为0,入射天顶角为44~48时,目标模拟器生成的红外图像对比度达到最佳,系统成像质量最好。     

基于视觉表达的工业设计合理性评估方法研究

为了提高工业设计的合理性评估能力,提出一种基于视觉表达和图像分析的工业设计合理性评估方法。以工业设计工件为例,首先采用数字扫描成像技术进行工业设计工件的视觉成像采集,对采集的工业设计工件视觉图像进行中值滤波降噪预处理,然后提取工件的边缘轮廓特征,采用Harris角点检测方法对工件的关键加工点进行定位检测和合理性评估。最后进行仿真测试分析,结果表明,采用该方法进行工业工件设计,对设计的合理性评估的准确性能更好,评价指标更明确。